[
https://issues.apache.org/jira/browse/ACCUMULO-2488?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Bill Havanki updated ACCUMULO-2488:
-----------------------------------
Resolution: Fixed
Status: Resolved (was: Patch Available)
I've committed the adjustment as reviewed. ACCUMULO-2494 is about updating the
standard deviation computation in {{o.a.a.core.util.Stat}}. Depending on how
that turns out, the updated capability could be reused here, replacing the
naive method I implemented. I'd be fine with either reopening this ticket to
put in that change or having it done under ACCUMULO-2494.
> Concurrent randomwalk balance check needs refinement
> ----------------------------------------------------
>
> Key: ACCUMULO-2488
> URL: https://issues.apache.org/jira/browse/ACCUMULO-2488
> Project: Accumulo
> Issue Type: Test
> Components: test
> Affects Versions: 1.4.4
> Reporter: Bill Havanki
> Assignee: Bill Havanki
> Priority: Minor
> Labels: randomwalk, test
> Fix For: 1.4.5, 1.5.2, 1.6.0
>
>
> The check for balanced tablets in the randomwalk Concurrent test too easily
> fails.
> Here is a real-life example from the test for the number of tablets across
> five tablet servers: 2, 5, 2, 2, 3. (An old unrelated table plays into these
> totals.) This produces a mean of 2.8. The cluster is considered unbalanced by
> the test when any server's count differs from the mean by the larger of 1 or
> the mean divided by 5. In this case, 2.8/5 is less than 1, so the second
> tablet server fails since it has more than 3.8 tablets. Even a 4 would fail.
> Part of the problem in this particular case is that there are so few tablets,
> and so few tablet servers. The cluster also seems happy to leave these counts
> as is, as I continue to check it, so the test's definition of unbalanced is
> too narrow.
> The test needs to be refined to detect unbalanced conditions with a
> statistically decent calculation.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
